#5 How to invite friends to Google+
i) Click on “Invite People to join Google+” link at right column of Chrome Google+
ii) If link above not available, simply share a comment/post/picture with friend’s email

#6 Google+Facebook
For those who want to catch up News feed from Facebook in Google+, try this extensions:Google+Facebook

#7 Android Google+ Photos/Videos Upload
– All photos and videos taken will auto upload to google+ private album
– Few useful options can be choose from setting-> Instant upload Setting
– Uncheck Instant Upload If you prefer upload manually.

#8 Android Google+ Push notification
Google+ has few options for huddle and general notification, check it out in Setting.